Here's why:
* It's a descriptive phrase. It's a simple, humorous way to describe someone who habitually procrastinates and leaves things to the last minute.
* Common Usage: It's likely a phrase that evolved organically from everyday language, used by people to express their frustration or amusement at someone's procrastination.
Similar Phrases:
There are several similar phrases that express the same idea, often with a playful or teasing tone:
* "Eleventh-hour Harry"
* "Deadline Dan"
* "Last-minute Larry"
Conclusion:
While the exact origin of "Last Minute Nelly" is unknown, it's a popular saying that likely arose from common usage to describe someone who procrastinates.